1. Field of the Invention
The present invention relates to a mobile device and location registration method for registering location information of the device itself.
2. Related Background Art
Currently, such mobile devices as portable telephones that can conduct voice communications and packet communications are widely known. At predetermined cycle this mobile device can register the location of the device itself to a control server for packet communications (for example, a SGSN, specifically, a Serving GPRS Support Node), and in addition, can register the location of the device itself to a control server for voice communications (for example, a VLR/MSC, specifically, a Visitor Location Register/Mobile Switching Center).
As the mobile device can register location information to the respective control servers at predetermined cycle in this way, the server side can ascertain where the mobile device is located, and can conduct call out processing to the mobile device. Further, the well-known technology according to Japanese Patent Application Laid-open No. 2000-23232 is technology that can register location information. Disclosed in this patent literature is a location information notification method and device that can conduct highly precise and efficient control of the location of a mobile station with the minimum necessary communications for location registration even if the mobile station is moving at a slow velocity.
In this regard, the access restriction, which comprises outgoing call restriction and incoming call restriction, is executed in order to prevent network congestion. Concretely, system information, which is information for confirming the location of the mobile device, is delivered from the base station to the mobile device. This system information comprises information indicating that communications to an certain terminal have been restricted, and the mobile device that has received this system information can determine whether or not the device itself is the target of the access restriction. This access restriction may be either the restriction of packet communications, the restriction of voice communications, or both.
Meanwhile, the location is registered with the control server for packet communications and control server for voice communications at every predetermined time (for example, 54 minutes) based on the mobile device registering the location with the control server for packet communications every predetermined time (for example, 54 minutes) timed by a timer, and then the location is registered with the control server for voice communications from the control server for packet communications (the so-called combined update).
However, this kind of combined update cannot be conducted when the control server for packet communications is under access restriction. For this reason, in current systems, if the control server for packet communications is under access restriction, the mobile device is configured to switch the interval of the timer, and to register the location at least with the control server for voice communications (including the control server for packet communications if the access restriction of the control server for packet communications has been released) every predetermined time (for example, 180 minutes, which is set to be longer than the aforementioned 54 minutes). By registering the location with the control server for voice communications in this way, at least the control server for voice communications can conduct call out processing for executing voice communications.
According to this configuration, if the control server for packet communications is under access restriction, the control server for packet communications can ascertain the location of the mobile device after 180 minutes have elapsed. Namely, the location of the mobile device cannot be ascertained for a long period of time. For this reason, the problem arises that, for example, call out processing cannot be executed in relation to the mobile device because the location has not been registered even though the control server for packet communications has released access restriction.